Heating device



FIG. 1 is a perspective view of a heating device showing our new design;

FIG. 2 is a front elevational view showing the design for the heating device of FIG. 1;

FIG. 3 is a rear elevational view showing the design for the heating device of FIG. 1;

FIG. 4 is a left side elevational view showing the design for the heating device of FIG. 1;

FIG. 5 is a right side elevational view showing the design for the heating device of FIG. 1;

FIG. 6 is a top plan view showing the design for the heating device of FIG. 1; and,

FIG. 7 is a bottom plan view showing the design for the heating device of FIG. 1.

The broken lines shown in the drawings illustrate portions of the heating device that form no part of the claimed design. 

CLAIM The ornamental design for a heating device, as shown and described. 